Question

I’m just coming off of my period. It ended yesterday. I’ve had a very tiny amount of spotting this morning. Tonight my husband and I were making out and it got a little carried away. We didn’t have penetrative sex but ejaculated on my underwear and I’m not sure if any got in me or not. I’m not on birth control because it gave me terrible side effects and he obviously didn’t wear a condom. How high of a chance do I have of getting pregnant?